Nested handle door lock assemblies for vending machine cabinets are widely utilized and have been well known in the prior art. Indeed, the recognition of this common usage is illustrated by the fact that dimensional standards have been set forth by NAMA (National Automatic Merchandising Association) and ASTM (American Society of Testing Materials). Moreover, a considerable number of patents have been issued on numerous different aspects of such pop-out handle assemblies as illustrated, for example, in Roop U.S. Pat. No. 4,552,001 and the numerous patent references identified therein which span a time period of over 60 years.
Such lock mechanisms commonly employ a housing of cylindrical structure having an integral rim flange which fits flush against the outside face of a door panel with the cylindrical portion projecting rearwardly through an opening in the door panel. Mounting screws or bolts extend through the countersunk holes in the rim flange underneath the handle to secure the lock housing against the door panel. Typically, a T-shaped handle containing the lock mechanism is received by the rim flange housing and when the lock mechanism is operated by a proper key, the handle pops out to render it accessible for manipulation to open or close the cabinet door. When the handle is turned to the door locking position, it can then be pushed in to nest within the recess of the rim flange housing where it becomes essentially flush with the rim and remains inaccessible to any attempted manipulation of the handle.
In addition to various types of key operated locks mounted in the handle portion, there have also been various types of locking mechanisms carried by the rim flange housing which affect the manner in which the door is opened and closed as well as for drawing a door tightly against a sealing gasket such as used in refrigerated vending machine cabinets. Typically, the rim flange housing carries a rotatable bolt member that has external threads and is threadably received in an internally threaded nut member on the cabinet with multiple rotational turns of the handle affecting the opening and closing. Alternatively, the bolt member can carry a cam latch or a bayonet connector member where the opening is accomplished by some fractional rotation of the handle such as what is commonly referred to as a 1/4 turn locking and unlocking operation. In either event, in many of the previous constructions, due to misalignments which occur between the lock assembly and cabinet connecting members there can be a slight bending moment on the rim flange housing which in turn can cause a binding with the nested lock handle that interferes either with the freedom of the handle to pop out or the ability to be easily pushed manually into the nested position.
One previous attempt to solve this problem was the provision of a universal type joint in the bolt member that would allow it to be self-aligning and avoid transmittal of a bending moment back up through the components to the handle. While the universal joint arrangement did provide a solution to the problem, it also was a complex machined arrangement that significantly added to the costs and difficulties of manufacture and assembly.